irssi scripting

I love irssi. I don't know any other irc client that even comes close for the sort of use I do. Recently, I've taken (with LOTS of help) to writing some scripts for irssi, the most useful of which (to me anyway) is one that logs channels I'm in to a mysql DB. I then use this DB along with some other scripts to get information about what is going on within my irssi client in a more convenient form.

As I'm going down this path in scripting, and figuring out how things work, I'm finding that some details are hard to come by. There really isn't that much documentation out there on how to do things, other than looking at other peoples scripts. Irssi is, of course, open source, so one can always go digging in the code. This can be rather time consuming though and seems a bit much for someone just interested in writing a quick and useful script.

Given this, I'm going to use this post as a sort of dumping ground for useful details I've had to dig for or ask for help with, in order to maybe save the next newbie a bit of time.